Immune environment in serrated lesions of the colon: intraepithelial lymphocyte density, PD-1, and PD-L1 expression correlate with serrated neoplasia pathway progression.

ABSTRACT: The serrated neoplasia pathway accounts for approximately 20% of colorectal carcinomas (CRCs). Sessile serrated adenomas (SSAs), the main precursor lesion of the serrated pathway, are molecularly driven by MLH1 promoter methylation and microsatellite instability (MSI) in their progression to CRC. MSI-high (MSI-H) lesions are highly immunogenic and associated with a high density of tumor-infiltrating lymphocytes. Our study's aim was to determine how the kinetics of this immune environment relates to SSAs in their progression through low-grade (SSA-LD) to high-grade dysplasia (SSA-HD) and CRC. We analyzed 74 cases (16 CRCs, 14 SSAs-HD, and 44 SSAs-LD). Cases of hyperplastic polyp and SSA without dysplasia were analyzed for comparison. MSI status, intraepithelial lymphocyte (IEL) density, and

SUBMITTER: Acosta-Gonzalez G 

PROVIDER: S-EPMC6365194 | biostudies-literature | 2019 Jan

REPOSITORIES: biostudies-literature